%D 2008 %0 In-Process %T Comparison of broiler performance and carcass yields when fed diets containing transgenic maize grains from event DP-O9814O-6 ( Optimum GAT ) , near-isogenic control maize grain , or commercial reference maize grains . %J Poult Sci %V 87 %P 2562-72 %A McNaughton J %A Roberts M %A Smith B %A Rice D %A Hinds M %A Rood T %A Layton R %A Lamb I %A Delaney B %M pub19038812 %X A genetically modified maize ( Zea mays L ) line that contains the Optimum GAT trait ( event DP-O9814O-6 ; 98140 ) was produced by integration of the gat4621 and zm-hra genes . The expressed GAT4621 and ZM-HRA proteins confer tolerance to the herbicidal active ingredient glyphosate and acetolactate synthase-inhibiting herbicides , respectively . The objective of this study was to compare the nutritional performance of 98140 maize grain to nontransgenic maize grain in a 42-d feeding trial in broiler chickens . Diets were prepared using grain from untreated 98140 plants and from plants treated with an in-field application of herbicides ( 98140 + Spray ) . For comparison , additional diets were produced with maize grain obtained from the nontransgenic near-isogenic control ( control ) and nontransgenic commercial reference Pioneer brand hybrids 33J56 , 33P66 , and 33R77 . Diets were fed to Ross x Cobb broilers ( n = 120/group , 50% male and 50% female ) in 3 phases : starter , grower , and finisher containing 58 . 5 , 64 , and 71 . 5% maize grain , respectively . No statistically significant differences were observed in mortality , growth performance variables , or carcass and organ yields between broilers consuming diets produced with maize grains from unsprayed or sprayed 98140 and those consuming diets produced with near-isogenic control maize grain . Additionally , all performance and carcass variables from control , 98140 , and 98140 + Spray test maize treatment groups were within tolerance intervals constructed using data from reference maize groups . Based on these results , it was concluded that 98140 maize grain ( unsprayed or sprayed with a herbicide mixture ) was nutritionally equivalent to nontransgenic control maize with comparable genetic background .